JP4904682B2 - Broad stripe type semiconductor laser device, broad stripe type semiconductor laser array using the same, and method for producing broad stripe type semiconductor laser device - Google Patents

Description

The present invention relates to a broad stripe semiconductor laser device having a window region for suppressing light absorption particularly at a main emission side end face, a broad stripe semiconductor laser array using the same, and a method for manufacturing a broad stripe semiconductor laser device.

2. Description of the Related Art In recent years, an infrared wavelength semiconductor laser using an AlGaAs-based material has been used for reading, rewriting, or initializing an optical disk such as a compact disk (CD). In addition, since AlGaAs semiconductor lasers have Nd: YAG, Nd: YVO _{4 and} other crystal absorption bands in the vicinity of 808 nm in solid-state excitation applications, they are broad stripe type infrared high-power semiconductors that oscillate transverse multimode laser light. It is also expected as a laser.

  Generally, the maximum light output of an AlGaAs semiconductor laser is determined by the light output at which end face destruction occurs. The end face breakage occurs because the crystal itself constituting the semiconductor laser melts due to the heat generated by the light absorption of the surface states of the end face region, and the function of the resonator is not achieved. Therefore, in order to realize a high output operation, it is necessary to devise a technique that does not cause end face destruction even at a higher light output. Therefore, conventionally, for example, an impurity such as silicon (Si) or zinc (Zn) is diffused on the end surface to make it difficult to absorb the laser beam, that is, to provide a window region that is transparent to the laser beam. (For example, refer to Patent Document 1).

  FIG. 34 shows an example of a conventional AlGaAs semiconductor laser element having such a window region. This semiconductor laser element has a window region formed by diffusing, for example, zinc (Zn) on its end face, and has, for example, an n-type cladding layer 113 and a quantum well structure on a substrate 111 made of n-type GaAs. An active layer 114, a p-type cladding layer 115, and a contact layer 118 are stacked in this order from the substrate 111 side. A part of the contact layer 118 and the p-type cladding layer 115 is a ridge 120 extending in a direction orthogonal to the paper surface in order to limit the stripe region of the active layer 114. A current blocking layer 121 is embedded in the outside.

  Further, in this semiconductor laser element, the window region 130 is formed by diffusing, for example, zinc (Zn) as an impurity in the main emission side end face 110F and the rear end face 110R facing the extending direction of the protrusion 120 and in the vicinity thereof. ing. The window region 130 reaches the active layer 114, and the disordered region 131 is formed by mixing atoms constituting the well layer and the barrier layer of the active layer 114. The disordered region 131 has a band gap energy larger than the effective band gap energy of the active layer 114 and is transparent to the laser light.

  A p-side electrode 141 is formed on the contact layer 118 and the current blocking layer 121, and an n-side electrode 142 is formed on the back side of the substrate 111.

FIG. 35 to FIG. 37 show an example of the manufacturing method of this conventional semiconductor laser device. First, for example, as shown in FIGS. 35A and 36, an n-type cladding layer 113, an active layer 114, a p-type cladding layer 115, and a contact layer 118 are formed in this order on a substrate 111. Next, similarly as shown in FIGS. 35A and 36, an insulating film 151 made of, for example, SiO ₂ is formed on the surface of the contact layer 118, and the insulating film 151 corresponds to the planned position of the resonator end face. Thus, an opening 151A is provided. Subsequently, as shown in FIGS. 35A and 36, the window region 130 is formed by diffusing, for example, zinc (Zn) as an impurity in the vicinity of the position where the resonator end face is to be formed using the insulating film 151 as a mask. Form. As a result, the disordered region 131 is formed in the portion where the window region 130 reaches the active layer 114.

Next, as shown in FIGS. 35B and 37, a striped mask 152 made of, for example, SiO ₂ is formed, and the contact layer 118 and a part of the p-type cladding layer 115 are etched using the mask 152. By doing so, the ridge 120 is formed.

Subsequently, as shown in FIG. 35C, a current blocking layer 121 is selectively grown on both sides of the protrusion 120 using a mask 152. Finally, the mask 152 is removed, and as shown in FIG. 34, the p-side electrode 141 and the n-side electrode 142 are formed, the substrate 111 is adjusted to a predetermined shape, and the main emission side end face 110F and the rear end face 110R are formed. To do.
JP-A-8-111560 JP 2003-78204 A (paragraph 0120)

  However, such a conventional manufacturing method has a problem that etching control is difficult and shape reproducibility is low because etching when forming the ridge 120 can only be controlled by etching time. Since the shape of the ridge 120 is a factor that determines the horizontal transverse mode of the semiconductor laser, an etching control method when forming the ridge 120 is extremely important. Nevertheless, conventionally, an etching control method that can reliably control the shape of the protrusion 120 has not been established.

For example, in Patent Document 1 described above, an etching stop layer made of a p-type Al _0.7 GaAs mixed crystal is provided in a p-type cladding layer made of a p-type Al _0.5 GaAs mixed crystal, and an organic acid and hydrogen peroxide solution are mixed. It is described that etching is controlled by an aluminum composition difference between a p-type cladding layer and an etching stop layer by using an etchant containing the etchant.

  However, since impurities are diffused in the crystal in the window region, the aluminum composition of the p-type cladding layer and the etching stop layer is broken, and the difference in the aluminum composition of both is broken. For this reason, the method described in Patent Document 1 has a problem in that etching does not stop at the etching stop layer and penetrates. When the etching reaches the active layer, the active layer at the end face disappears, and in addition, many inactive levels are formed at the end face by the oxidizing action of the etchant, and the light generated inside the active layer It can no longer be taken out. That is, the function as a semiconductor laser is completely lost.

Incidentally, in Patent Document 2, it is proposed to use a hydrofluoric acid type etchant as an etchant, but the hydrofluoric acid type etchant dissolves a mask 152 made of SiO ₂ covering the upper surface of the protrusion 120. Therefore, it becomes difficult to form the current blocking layers 121 on both sides of the ridge 120 after the ridge 120 is formed. Although it is possible to use a sulfuric acid-based etchant, a layer having a small aluminum composition is less likely to be etched with respect to a sulfuric acid-based etchant. Therefore, even if etching selectivity is obtained, the aluminum composition of the etching stop layer is set to p. It must be much smaller than the mold cladding layer, which may affect the band structure and the longitudinal refractive index distribution.

  In addition to the above, when the window region is applied to a broad stripe semiconductor laser in the infrared wavelength band, it is necessary to further satisfy some requirements. In the use of the broad stripe type semiconductor laser, it is desirable that the horizontal transverse mode is stable and the radiation angle in the transverse direction is narrow in view of its use. Stabilization of the horizontal transverse mode is particularly important when coupled to an optical fiber or when absorbed in a crystalline medium for solid excitation applications. This is because it affects the instability of the wavelength and the fluctuation of the spectrum due to the return light. Regarding the radiation angle in the lateral direction, for example, when laser light is radiated to a crystal medium, it is naturally better that the beam spot is small. However, there is a trade-off relationship between the stability of the horizontal transverse mode and the magnitude of the radiation angle that the radiation angle is larger as the horizontal transverse mode is more stable. Therefore, it has been extremely difficult to realize a broad stripe type semiconductor laser having both of these and having a window region.

The present invention has been made in view of such problems, and the object thereof is to provide a high power operation by providing a window region, and to improve the shape accuracy of the protrusion and the reproducibility in the manufacturing process. broad-stripe semiconductor laser device and a broad stripe semiconductor laser array using the same, and an object of the invention to provide a method for producing a broad-stripe semiconductor laser device.

Broad-stripe semiconductor laser device according to the present invention, the first clad layer on a substrate, the active layer, the second cladding layer, the etching stop layer, the third cladding layer and including a semiconductor layer having a contact layer in this order, the first cladding layer , The active layer, the second cladding layer, the etching stop layer, and the third cladding layer include at least aluminum (Al) and gallium (Ga) among the group 3B elements and at least arsenic (As) among the group 5B elements. The contact layer is made of GaAs, the third cladding layer and the contact layer are protrusions for limiting the stripe region of the active layer, and protrude from the side surface of the semiconductor layer. Bei example a pair of resonator end surface opposed to the extending direction of the ridges, at least one of the cavity end face, generated in the active layer Was is formed a window region for suppressing absorption of light, width W1 of the protruding portion in the region near the end surface including the window area is much larger than the width W2 in regions other than the region near the end surface, and window region And the dimension LA in the resonator direction from the resonator end face in the region near the end face is larger than the dimension LW in the resonator direction from the resonator end face in the window region .

  Here, the “width” refers to a dimension in a direction perpendicular to both the extending direction of the protrusion, that is, the resonator direction, and the stacking direction of the semiconductor layers.

The broad stripe semiconductor laser array according to the present invention comprises a plurality of broad stripe semiconductor laser elements according to the present invention arranged in parallel.

According to a method of manufacturing a broad stripe semiconductor laser device according to the present invention , a semiconductor layer having a first cladding layer, an active layer, a second cladding layer, an etching stop layer, a third cladding layer, and a contact layer in this order is formed on a substrate . The first cladding layer, the active layer, the second cladding layer, the etching stop layer, and the third cladding layer are made of at least aluminum (Al) of the group 3B element and gallium (Ga) and at least arsenic (As) of the group 5B element. Is generated in the active layer by diffusing impurities in at least one of the step of forming the contact surfaces of the pair of resonators in the semiconductor layer. forming a window region for suppressing the absorption of light, a contact layer and a third class Some of de layer so as to form a ridge portion for limiting the stripe region of the active layer is removed by etching until the etching stop layer is exposed, the width of the ridges in the region near the end surface including the window area the W1, much larger than the width W2 in the region other than the region near the end surface, and not less than the width W3 of the window region, the dimension LA in the resonator direction from forming predetermined position of the cavity end face of the region near the end surface, the window region A step of making the dimension larger than the dimension LW in the direction of the resonator from the position where the resonator end face is to be formed, and a step of forming a pair of resonator end faces facing the extending direction of the protrusion on the side surface of the semiconductor layer. It is what.

In the broad stripe semiconductor laser device of the present invention or the broad stripe semiconductor laser array of the present invention, the width W1 of the protrusion in the region near the end surface including the window region is larger than the width W2 in the region other than the region near the end surface. In addition, since the width of the window region is equal to or greater than W3, the difference in refractive index between the protrusion and the outside increases in a region other than the region near the end face, and the horizontal transverse mode during laser oscillation is stabilized. On the other hand, in the region near the end surface including the window region, there is no difference in refractive index between the protrusion and the outside thereof, or it becomes extremely small, and the beam radiation angle in the lateral direction becomes narrow.

In the manufacturing method of the broad stripe type semiconductor laser device of the present invention, when forming the ridge by etching away a part of the semiconductor layer, the width W1 of the ridge in the region near the end surface including the window region, much larger than the width W2 in the region other than the region near the end surface, and the said window region width W3 above, the dimension LA in the resonator direction from forming predetermined position of the cavity end face of the region near the end surface, the cavity of the window area Since it is made larger than the dimension LW in the resonator direction from the position where the end face is to be formed, etching of the window region to the active layer is suppressed. Therefore, the protruding portion is accurately manufactured, and the shape reproducibility is also improved.

According to the broad stripe type semiconductor laser device of the present invention or the method of manufacturing the broad stripe type semiconductor laser device of the present invention, the width W1 of the protrusion in the region near the end surface including the window region is set in the region other than the region near the end surface. much larger than the width W2, and a width W3 over the window area, the dimension LA in the resonator direction from the cavity end face of the region near the end surface, larger than the dimension LW in the resonator direction from the cavity end face of the window region since the way, in the case where a window region for the high output can also be high shape accuracy of the ridge. Therefore, it is possible to stabilize the horizontal transverse mode and reduce the beam radiation angle in the transverse direction. In addition, the shape of the protruding portion can be controlled with low cost and good reproducibility by a simple manufacturing process.

According to the broad stripe type semiconductor laser array of the present invention, since the broad stripe type semiconductor laser device of the present invention is provided, the horizontal transverse mode is stabilized, the beam radiation angle in the lateral direction is reduced, and the output is high and the reliability is improved. A broad stripe type semiconductor laser array having a high height can be realized.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 schematically shows the overall configuration of a semiconductor laser array according to an embodiment of the present invention. This semiconductor laser array 1 is used as a laser welding light source, a solid excitation light source, or the like, and has a configuration in which a plurality of semiconductor laser elements 10 (for example, three in FIG. 1) described later are arranged in parallel.

  FIG. 2 is an enlarged view of the semiconductor laser element 10 constituting the semiconductor laser array 1 shown in FIG. 1, and a part of the semiconductor laser element 10 is cut away to show the internal configuration. This semiconductor laser device includes, for example, a buffer layer 12, an n-type first cladding layer 13, an active layer 14, a p-type second cladding layer 15, an etching stop layer 16, a p-type third cladding layer 17 and the like on a substrate 11. The contact layers 18 are sequentially stacked. The contact layer 18 and the p-type third cladding layer 17 are formed as ridges 20 for limiting the stripe region 14A of the active layer 14, and current blocking layers 21 are provided on both sides of the ridges 20. Is formed.

  Further, on the side surface of the substrate 11 or the p-type third cladding layer 17, a pair of resonator end faces opposed to the extending direction of the ridges 20, that is, a main emission side (front side) end face 10F and a rear (rear side) end face 10R is formed. Each of the main emission side end face 10F and the rear end face 10R is formed with a window region 30 for suppressing absorption of light generated in the active layer 14 by diffusing, for example, zinc (Zn) as an impurity. Yes.

  As shown in FIGS. 1 and 3, the width W1 of the protrusion 20 in the end surface vicinity region 30A including the window region 30 is larger than the width W2 in the element internal region 30B other than the end surface vicinity region 30A. That is, the protrusion 20 does not extend in the end face vicinity region 30 </ b> A including the window structure 30, and the p-type third cladding layer 17 remains. Thereby, in this semiconductor laser device 10, even when the window region 30 is provided for high output, the shape accuracy of the protruding portion 20 can be increased in the end surface vicinity region 30A including the window region 30, The horizontal transverse mode can be stabilized and the beam radiation angle in the transverse direction can be reduced.

  Further, the width W1 of the ridge portion 20 in the end face vicinity region 30A including the window region 30 is preferably equal to or larger than the width W3 of the window region 30 as shown in FIG. This is because the shape accuracy of the protrusion 20 can be further improved.

  The distance between the main emission side end face 10F and the rear end face 10R, that is, the resonator length L of the semiconductor laser element 10 is, for example, 700 μm, and the cavity direction from the main emission side end face 10F or the rear end face 10R of the window region 30 The dimension LW at 20 is, for example, 20 μm, and the dimension LA in the resonator direction from the main emission side end face 10F or the rear end face 10R of the end face vicinity area 30A including the window area 30 is, for example, 30 μm.

The substrate 11 is made of n-type GaAs to which an n-type impurity such as silicon (Si) or selenium (Se) is added, for example. The buffer layer 12 has, for example, a thickness in the stacking direction (hereinafter simply referred to as “thickness”) of 0.5 μm and is made of n-type GaAs to which an n-type impurity such as silicon (Si) or selenium (Se) is added. Has been. The n-type first cladding layer 13 has a thickness of 1.5 μm, for example, and is composed of an n-type Al _0.47 GaAs mixed crystal to which an n-type impurity such as silicon (Si) or selenium (Se) is added.

The active layer 14 has at least one quantum well structure and is composed of an AlGaAs mixed crystal to which no impurity is added. The active layer 14 may be, for example, an SCH (Separate Confinement Heterostructure) superlattice active layer, and the layer structure is not particularly limited. In particular, in the case of the broad stripe type, it is preferable to have a SQW (Single Quantum Well) structure. Specifically, the active layer 14 has, for example, an SCH structure, and has an Al _x1 Ga _1-x1 As (x1 = 0.1) thickness of 0.01 μm as shown in FIG. It has an SQW structure in which an optical waveguide layer 14W made of a mixed crystal is sandwiched between guide layers 14G made of Al _x2 Ga _1-x2 As (x2 = 0.3) mixed crystal having a thickness of 0.05 μm.

In the portion of the active layer 14 that overlaps the window region 30, atoms of the optical waveguide layer 14W and the guide layer 14G are mixed to form a disordered region 31 made of Al _x3 Ga _1-x3 As (x3≈x1) mixed crystal. Has been. The effective band gap energy of the disordered region 31 is substantially equal to the guide layer 14G, as shown in FIG. 4B. That is, the disordered region 31 has a band gap energy larger than the effective band gap energy of the active layer 14 and is transparent to the laser light generated in the active layer 14.

The p-type second cladding layer 15 has a thickness of, for example, 0.3 μm and is composed of a p-type Al _0.47 GaAs mixed crystal to which a p-type impurity such as zinc (Zn), magnesium (Mg), or beryllium (Be) is added. Has been.

  The etching stop layer 16 and the p-type third cladding layer 17 are made of AlGaAs mixed crystal, and the aluminum composition contained in the p-type third cladding layer 17 is lower than the aluminum composition contained in the etching stop layer 16, and the difference Is preferably 0.025 or more. Etching selectivity between the etching stop layer 16 and the p-type third cladding layer 17 with respect to an etchant made of a mixed solution of an organic acid and hydrogen peroxide solution when forming the protrusion 120 in the manufacturing process described later. It is because it can take large. Furthermore, it is more preferable if the thickness of the etching stop layer 16 is 0.02 μm or more. This is because there is little influence on the refractive index distribution in the vertical direction, the influence on the optical characteristics can be suppressed, epitaxial growth is facilitated in the manufacturing process, and the growth time is shortened.

Specifically, the etching stop layer 16 has, for example, a thickness of 0.02 μm and is composed of Al _0.55 GaAs mixed crystal. The p-type third cladding layer 17 has a thickness of, for example, 1.2 μm, and a p-type Al _0.47 GaAs mixed crystal to which a p-type impurity such as zinc (Zn), magnesium (Mg), or beryllium (Be) is added. It is comprised by.

  For example, the contact layer 18 has a thickness of 0.5 μm and is made of p-type GaAs to which a p-type impurity such as zinc (Zn), magnesium (Mg), or beryllium (Be) is added.

  The contact layer 18 is preferably formed avoiding the end face vicinity region 30 </ b> A including the window region 30. Since the light is not generated in the vicinity of the end face region 30A including the window region 30 so that light is not generated and the light from the inside of the element is guided, the light density at the main emission side end face 10F can be reduced. This is because the effect of the present invention can be further enhanced.

  Furthermore, it is more preferable that the contact layer 18 is formed so as to avoid a part of the element internal region 30B adjacent to the end face vicinity region 30A. It is because it can suppress reliably that an electric current is inject | poured in the part which widened the width | variety W1 of the protrusion part 20. FIG. Therefore, the distance LC between the contact layer 18 and the main emission side end face 10F or the rear end face 10R is longer than the dimension LA of the end face vicinity region 30A, for example, 40 μm.

  The current blocking layer 21 is formed so as to embed the slope of the ridge 20 and the element internal region 30B, and is made of, for example, n-type GaAs doped with an n-type impurity such as silicon (Si) or selenium (Se). Has been.

  In the semiconductor laser device 10, a p-side electrode 41 is provided on the contact layer 18 and the current blocking layer 21, and an n-side electrode 42 is provided on the back side of the substrate 11. The p-side electrode 41 is made of, for example, Ti / Pt / Au, and the n-side electrode 42 is made of, for example, AuGe / Ni / Au / Ti / Pt / Au. Similarly to the contact layer 18, the p-side electrode 41 is preferably formed so as to avoid the end face vicinity region 30 </ b> A including the window region 30. This is because current injection in the end face vicinity region 30A including the window region 30 can be reliably prevented, and a higher effect can be obtained.

  The semiconductor laser array 1 including the semiconductor laser element 10 can be manufactured as follows, for example.

  FIG. 5 shows the flow of the manufacturing method of the semiconductor laser device 10, and FIGS. 6 to 23 show the steps in order. First, as shown in FIG. 6, on the substrate 11 made of the above-described material, for example, MOVPE (Metal Organic Vapor Phase Epitaxy) method or MOCVD (Metal Organic Chemical Vapor Deposition); Growth) method, the buffer layer 12, the n-type first cladding layer 13, the active layer 14, the p-type second cladding layer 15, the etching stop layer 16, the p-type third cladding layer 17 and the above-described thicknesses and materials, respectively. Contact layers 18 are sequentially stacked (step S101). At this time, for example, silicon (Si) or selenium (Se) is used as the n-type impurity, and, for example, zinc (Zn), magnesium (Mg), or beryllium (Be) is used as the p-type impurity. Thereby, a stacked body of semiconductor layers having a double hetero structure is formed on the substrate 11.

Next, as shown in FIG. 6, an insulating film 51 made of, for example, SiO ₂ and a photoresist film (not shown) are sequentially formed on the contact layer 18 by, eg, CVD (Chemical Vapor Deposition). For example, a photoresist film (not shown) is formed into a predetermined shape by photolithography. Subsequently, by etching the insulating film 51 using this photoresist film as a mask, an opening 51A is formed corresponding to the planned formation positions of the main emission side end face 10F and the rear end face 10R. At this time, the dimension of the opening 51A in the resonator direction is, for example, 40 μm. Thereafter, the photoresist film (not shown) is removed.

  After the opening 51A is formed in the insulating film 51, as shown in FIG. 7, for example, zinc (Zn) as an impurity is diffused in the semiconductor crystal through the opening 51A of the insulating film 51 to thereby form the window region. 30 is formed (step S102). As diffusion conditions, for example, the gas phase is made a zinc (Zn) atmosphere, and thermal diffusion treatment is performed at a temperature of, for example, 500 ° C. to 700 ° C. or higher while applying arsenic (As) pressure. By this thermal diffusion treatment, impurities reach the active layer 14 and the disordered region 31 is formed. After that, as shown in FIG. 8, the insulating film 51 is removed.

After removing the insulating film 51, as shown in FIG. 9, an SiO ₂ film and a photoresist film (not shown) are sequentially formed on the contact layer 18 by, eg, CVD, and not shown by, for example, photolithography. A photoresist film is formed into a predetermined shape. Subsequently, the SiO ₂ film is etched using this photoresist film as a mask to form a mask 52 for forming the protrusions 20, and thereafter, the photoresist film (not shown) is removed. The mask 52 may be provided so as to completely cover the end face vicinity region 30A and cover a part of the element internal region 30B. As for the dimension of the mask 52, the dimension D1 in the part covering the end face vicinity region 30A including the window region 30 and a part of the element internal region 30B is 60 μm, for example, and the dimension D2 in the other element internal region 30B is 100 μm, for example To do.

  After forming the mask 52, as shown in FIGS. 10, 11, and 12, the contact layer 18 and a part of the third p-type cladding layer 17 are removed by etching using the mask 52, and the protruding portion is formed. 20 and the width W1 of the protrusion 20 in the end face vicinity region 30A including the window region 30 is made larger than the width W2 in the element internal region 30B (step S103). As a result, even when the difference in aluminum composition between the etching stop layer 16 and the third p-type cladding layer 17 is broken in the window region 30 in which the impurity is diffused, and the etching selectivity between the two is not obtained, the window region 30 is etched. Thus, penetration to the active layer 14 is suppressed. Therefore, the protrusion 20 can be produced with high accuracy and the shape reproducibility can be improved.

As an etchant used when forming the protrusion part 20, the liquid mixture of a citric acid and hydrogen peroxide solution is preferable, for example. The mixed solution of citric acid and hydrogen peroxide water exhibits etching selectivity between the third p-type cladding layer 17 made of Al _0.47 GaAs mixed crystal and the etching stop layer 16 made of Al _0.55 GaAs mixed crystal, and the etching stop. This is because the etching can be automatically stopped by being rapidly oxidized when the layer 16 is exposed. Further, the manufacturing cost can be reduced by using an inexpensive mixed solution of citric acid and hydrogen peroxide solution as an etchant without requiring a particularly complicated etching technique for forming the protrusion 20. Because.

  Specifically, for example, it is preferable to contain citric acid and hydrogen peroxide solution in a volume ratio of citric acid monohydrate (50 wt% aqueous solution): hydrogen peroxide solution (31%) = 12: 1. . In the following description, the mixing ratio of the etchant is a volume ratio unless otherwise specified.

  After forming the ridge 20, the current blocking layer made of the above-described material is formed on both sides of the ridge 20 by selective epitaxial growth using a mask 52, as shown in FIGS. 21 is formed (step S104). The current blocking layer 21 is formed on the slope of the protrusion 20 and the surface of the etching stop layer 16 and is not formed on the mask 52. After that, the mask 52 is removed as shown in FIG.

  After removing the mask 52, as shown in FIG. 17, a photoresist film 53 is formed on the contact layer 18 and the current blocking layer 21, and an end face vicinity region 30 </ b> A including the window region 30 is formed on the photoresist film 53. Correspondingly, an opening 53A is provided. The opening 53A is desirably provided so that the end face vicinity region 30A is completely exposed and a part of the element internal region 30B adjacent thereto is exposed.

  After the opening 53A is provided in the photoresist film 53, as shown in FIGS. 18, 19, and 20, contact of the end face vicinity region 30A including the window region 30 is performed by etching using the photoresist film 53 as a mask. The layer 18 is removed (step S105). At this time, when the opening 53A is provided so as to expose the end surface vicinity region 30A and a part of the element internal region 30B adjacent thereto, a part of the current blocking layer 21 is also etched away together with the contact layer 18. .

As an etchant at this time, for example, it is preferable to use a mixed solution of ammonia water and hydrogen peroxide solution. The mixed solution of ammonia water and hydrogen peroxide solution etches the contact layer 18 made of p-type GaAs and the current blocking layer 21 made of n-type GaAs, but the p-type third cladding layer 17 made of p-type Al _0.47 GaAs. Etching is stopped when the p-type third cladding layer 17 is exposed. At this time, a part of the current blocking layer 21 is also etched at the same time in the element internal region 30B. However, in this region, there is no layer having a function of stopping the etching in the lower layer. Since some of these are excessively etched, it is necessary to control the time allowed.

  After removing the contact layer 18 in the end face vicinity region 30A including the window region 30, the photoresist film 53 is removed as shown in FIG.

  After removing the photoresist film 53, as shown in FIG. 22, the p-side electrode 41 made of the above-described material is formed on the contact layer 18 and the current blocking layer 21, and the back-side substrate 11 is made of the above-mentioned material. The n-side electrode 42 is formed (step S106). Finally, as shown in FIG. 23, the main exit side end face 10F and the rear end face 10R are formed by cleaving in the window region 30 in a direction orthogonal to the resonator direction (step S107), and a predetermined length. The laser bar. Thereby, the semiconductor laser array 1 in which the plurality of semiconductor laser elements 10 shown in FIG. 1 are arranged in parallel is completed.

  In the semiconductor laser element 10 or the semiconductor laser array 1 including the semiconductor laser element 10, when a predetermined voltage is applied between the p-side electrode 41 and the n-side electrode 42, the holes are formed in the contact layer 18, the p-type third cladding. The layer 17, the etching stop layer 16 and the p-type second cladding layer 15 are injected into the active layer 14, and the electrons are injected into the active layer 14 through the substrate 11, the buffer layer 12 and the n-type first cladding layer 13, and active In the layer 14, stimulated emission light is generated by recombination of electrons and holes. If the amount of injected carriers becomes sufficiently high and light exceeding the waveguide loss is generated, laser oscillation occurs, and this light is emitted to the outside from the main emission side end face 10F. Here, since the width W1 of the protrusion 20 in the end surface vicinity region 30A including the window region 30 is larger than the width W2 in the element internal region 30B other than the end surface vicinity region 30A, the protrusion in the element internal region 30B. The difference in refractive index between the strip 20 and the outside increases, and the horizontal and transverse modes during laser oscillation are stabilized. On the other hand, in the end face vicinity region 30 </ b> A including the window region 30, there is no difference in refractive index between the protrusion 20 and the outside thereof, or it becomes extremely small, and the beam radiation angle in the lateral direction becomes narrow.

  As described above, in the present embodiment, the width W1 of the ridge portion 20 in the end surface vicinity region 30A including the window region 30 is made larger than the width W2 in the element internal region 30B other than the end surface vicinity region 30A. Even when the window region 30 is provided for high output, the shape accuracy of the protrusion 20 can be increased. Therefore, the horizontal transverse mode can be stabilized and the beam radiation angle in the transverse direction can be reduced, and the semiconductor laser array 1 with high output and high reliability can be realized. Further, the shape of the protruding portion 20 can be controlled with a simple manufacturing process at low cost and with good reproducibility.

[Modification 1]
FIG. 24 shows a modification of the manufacturing method of the semiconductor laser device 10 according to the above embodiment, and FIGS. 25 to 29 show the process. This modification considers the difference in zinc (Zn) diffusion rate depending on the material, and removes a part of the contact layer 18 before forming the window region 30 to facilitate diffusion control and shorten the diffusion time. It is a thing. Note that the same steps as those in the manufacturing method of the above-described embodiment will be described using the same reference numerals with reference to the drawings.

  First, as shown in FIG. 25, the buffer layer 12, the n-type first cladding layer 13, the active layer 14, and the p-type are formed on the substrate 11 by the process shown in FIG. The second cladding layer 15, the etching stop layer 16, the p-type third cladding layer 17, and the contact layer 18 are sequentially stacked (step S101).

  Next, a photoresist film 53 is formed on the contact layer 18 by the process shown in FIG. 17, and the main emission side end face 10F and the rear end face 10R are formed on the photoresist film 53. An opening 53A is provided corresponding to the planned position. Subsequently, as shown in FIG. 25, the formation positions of the main emission side end face 10F and the rear end face 10R, and the positions thereof, by the steps shown in FIGS. The nearby contact layer 18 is removed (step S201). This removes the contact layer 18 whose zinc (Zn) diffusion speed is considerably slower than that of the p-type third cladding layer 17 made of a p-type Al0.47GaAs mixed crystal, so that zinc (Zn) diffusion control can be easily performed. In addition, the diffusion layer becomes thinner and the distance to the active layer 14 becomes shorter, so that the diffusion time can be shortened. After removing the contact layer 18, the photoresist film 53 is removed.

  After the removal of the photoresist film 53, as shown in FIG. 26, an opening is formed on the contact layer 18 and the p-type third cladding layer 17 by the process shown in FIG. An insulating film 51 having 51A is formed.

  After forming the insulating film 51, as shown in FIG. 26, the process shown in FIG. 7 is followed by the step shown in FIG. The window region 30 is formed by diffusing Zn) into the semiconductor crystal (step S102). At this time, the impurities reach the active layer 14 by the thermal diffusion treatment, and the disordered region 31 is formed. After that, the insulating film 51 is removed.

  After removing the insulating film 51, as shown in FIG. 27, the mask 52 for forming the protrusions 20 on the contact layer 18 is formed in the same manner as in the above embodiment by the process shown in FIG. Form.

  After the mask 52 is formed, as shown in FIG. 28, the contact layers 18 and 18 are etched by etching using the mask 52 in the same manner as in the above embodiment by the steps shown in FIGS. A portion of the third p-type cladding layer 17 is removed to form the ridge portion 20, and the width W1 of the ridge portion 20 in the end face vicinity region 30A including the window region 30 is made larger than the width w2 in the element internal region 30B. Increase (step S103).

  After forming the ridges 20, as shown in FIG. 29, by selective epitaxial growth using the mask 52 by the steps shown in FIGS. 13, 14, and 15, on both sides of the ridges 20, The current blocking layer 21 made of the above-described material is formed (Step S104).

  After forming the current blocking layer 21, the p-side electrode 41 is formed on the contact layer 18 and the current blocking layer 21 and the n-side electrode 42 is formed on the back side of the substrate 11 by the process shown in FIG. 22 (step S106). ). Finally, the main emission side end face 10F and the rear end face 10R are formed by the process shown in FIG. 23 (step S107) to obtain a laser bar having a predetermined length. Thereby, the semiconductor laser array 1 in which the plurality of semiconductor laser elements 10 shown in FIG. 1 are arranged in parallel is completed.

  As described above, according to the present modification, the window region 30 is formed after the planned formation positions of the main emission side end surface 10F and the rear end surface 10R and the contact layer 18 in the vicinity thereof are removed. Diffusion control of zinc (Zn) during formation can be facilitated and the diffusion time can be shortened.

  In this modification, the case where the window region 30 is formed after the formation positions of the main emission side end face 10F and the rear end face 10R and the contact layer 18 in the vicinity thereof is removed has been described. The window region 30 may be formed after removing the contact layer 18 and the p-type third cladding layer 17 in the vicinity of the position where the rear end face 10R is to be formed.

[Modification 2]
FIG. 30 shows another modification of the method for manufacturing the semiconductor laser device 10 according to the above embodiment, and FIG. 31 shows the process. In this modified example, when the contact layer 18 and the p-type third cladding layer are removed by etching in the step of forming the protrusions 20, the etchant is divided into a plurality of times and different etchants are used. Note that the same steps as those in the manufacturing method of the above-described embodiment will be described using the same reference numerals with reference to the drawings.

  First, according to the process shown in FIG. 6, the buffer layer 12, the n-type first cladding layer 13, the active layer 14, the p-type second cladding layer 15, and the etching stop are formed on the substrate 11 in the same manner as in the above embodiment. The layer 16, the p-type third cladding layer 17, and the contact layer 18 are sequentially stacked (step S101).

  Next, similarly to the above embodiment, the insulating film 51 having the opening 51A is formed on the contact layer 18 by the process shown in FIG.

  After forming the insulating film 51, for example, zinc (Zn) as an impurity is diffused into the semiconductor crystal through the opening 51 </ b> A of the insulating film 51 by the process shown in FIG. Thus, the window region 30 is formed (step S102). At this time, the impurities reach the active layer 14 by the thermal diffusion treatment, and the disordered region 31 is formed. After that, the insulating film 51 is removed by the process shown in FIG.

  After the insulating film 51 is removed, a mask 52 for forming the protrusions 20 is formed on the contact layer 18 by the process shown in FIG.

  After the mask 52 is formed, as shown in FIG. 31, the contact layer 18 and a part of the p-type third cladding layer 17 are partially removed by etching using the mask 52, for example, using a sulfuric acid-based etchant. It is removed (step S301). At this time, after the contact layer 18 is removed, the etching time is controlled to stop the etching in the middle of the third p-type cladding layer 17 so that the etching does not reach the etching stop layer 16. Note that it is extremely difficult to generate etching selectivity between the p-type third cladding layer 17 and the etching stop layer 16 by using a sulfuric acid-based etchant.

  Examples of the sulfuric acid-based etchant used here include sulfuric acid, hydrogen peroxide solution, and water in a volume ratio of sulfuric acid (96%): hydrogen peroxide solution (31%): water = 1: 8: 40. Preferably, the etching time is, for example, 2 minutes, and the thickness of the remaining p-type third cladding layer 17 is, for example, approximately 0.2 μm.

  After removing the contact layer 18 and a part of the p-type third cladding layer 17, the remaining part of the p-type third cladding layer 17 is washed with a citric acid aqueous solution without washing with running water and drying (step S <b> 302). Thereby, natural oxidation due to drying of the surface of the p-type third cladding layer 17 can be suppressed without exposing the substrate 11 to the atmosphere or water. Therefore, even if a mixed solution of citric acid and hydrogen peroxide solution is used as an etchant when the remaining portion of the p-type third cladding layer 17 is etched away as will be described later, the etching is effected by the effect of the outermost oxide film. It becomes possible to suppress the occurrence of white turbidity and uneven etching.

  This cleaning step is preferably performed twice or more by changing the cleaning liquid, for example. That is, first, the substrate 11 is immersed in a cleaning solution made of citric acid monohydrate (50 wt% aqueous solution), and the sulfuric acid-based etchant remaining on the surface of the substrate 11 is removed while stirring the cleaning solution for 20 seconds, for example. Note that when the substrate 11 is moved to the cleaning liquid, it is desirable to perform in an inert atmosphere or vacuum so that the surface is not exposed to the air or water in order to suppress natural oxidation due to drying of the surface.

  Next, in order to completely remove the generated surface natural oxide film and sulfuric acid-based etchant, the substrate 11 is immersed in another new cleaning solution made of citric acid monohydrate (50 wt% aqueous solution), and the cleaning solution is stirred for 1 minute, for example. And rinse. In addition, when the substrate 11 is moved to a new cleaning solution, it is desirable to perform in an inert atmosphere or vacuum so as not to expose the surface to the atmosphere or water in order to suppress natural oxidation due to drying of the surface. Also do not.

  After performing the cleaning process, the remaining portions of the third p-type cladding layer 17 are removed by etching using the mask 52 in the same manner as in the above embodiment by the processes shown in FIGS. The ridge 20 is formed, and the width W1 of the ridge 20 in the end face vicinity region 30A including the window region 30 is made larger than the width w2 in the element internal region 30B (step S303).

  As an etchant used when removing the remainder of the third p-type cladding layer, for example, a mixed solution of citric acid and hydrogen peroxide is preferable. Etching using a sulfuric acid-based etchant has low reproducibility and in-plane uniformity, and variations in etching have occurred within the surface of the substrate 11, but a mixed solution of citric acid and hydrogen peroxide is used as an etchant. This is because etching unevenness can be improved.

  Specifically, for example, as in the above-described embodiment, citric acid and hydrogen peroxide solution are mixed with citric acid monohydrate (50 wt% aqueous solution): hydrogen peroxide solution (31%) = 12: 1. What contains by volume ratio is preferable.

  For example, when the thickness of the remaining p-type third cladding layer 17 is about 0.2 μm, the etching time may be at least about 1 minute, for example, but slightly longer, for example, about 2 minutes. preferable. This is because the etching unevenness caused by the sulfuric acid-based etchant can be effectively eliminated.

  In addition, when the substrate 11 after the cleaning process is immersed in an etchant for etching the remaining portion of the p-type third cladding layer 17, the surface is exposed to air or water in order to suppress natural oxidation due to drying of the surface. It is desirable to carry out in an inert atmosphere or a vacuum so that there is no pretreatment with running water.

  After the remaining portion of the p-type third cladding layer 17 is removed, the above-described materials are formed on both sides of the protrusion 20 by selective epitaxial growth using the mask 52 by the steps shown in FIGS. A current blocking layer 21 is formed (step S104).

  After forming the current blocking layer 21, a photoresist film 53 having an opening 53A is formed on the contact layer 18 and the current blocking layer 21 by the process shown in FIG.

  After the photoresist film 53 is formed, the vicinity of the end surface including the window region 30 is etched by the steps shown in FIGS. 18, 19 and 20 in the same manner as in the above embodiment, using the photoresist film 53 as a mask. The contact layer 18 in the region 30A is removed (step S105). After that, the photoresist film 53 is removed by the process shown in FIG.

  After removing the photoresist film 53, the p-side electrode 41 is formed on the contact layer 18 and the current blocking layer 21 and the n-side electrode 42 is formed on the back side of the substrate 11 by the process shown in FIG. 22 (step S106). ). Finally, the main emission side end face 10F and the rear end face 10R are formed by the process shown in FIG. 23 (step S107) to obtain a laser bar having a predetermined length. Thereby, the semiconductor laser array 1 in which the plurality of semiconductor laser elements 10 shown in FIG. 1 are arranged in parallel is completed.

  As described above, according to this modification, when the contact layer 18 and the p-type third cladding layer 17 are removed by etching, different etchants are used in a plurality of times. The inner uniformity can be improved, and the protrusion 20 can be formed with higher accuracy.

  While the present invention has been described with reference to the embodiment, the present invention is not limited to the above embodiment, and various modifications can be made. For example, in the above embodiment, the case where the present invention is applied to the bar-shaped semiconductor laser array 1 in which a plurality of semiconductor laser elements 10 are arranged in parallel has been described. However, the present invention can also be applied to a semiconductor laser chip. When manufacturing a semiconductor laser chip, the substrate 11 is cleaved to an arbitrary length when the substrate 11 is adjusted to a predetermined size to form a laser bar, and further cleaved in a direction parallel to the resonator direction. Can be separated into individual chips.

  Moreover, in the said embodiment, the window area | region 30 is formed in the shape orthogonal to a resonator direction, and the width W1 of the protrusion part 20 in the end surface vicinity area | region 30A containing the window area | region 30 is set to the width | variety of the window area | region 30. The case where the width W1 is equal to W3 has been described. For example, as illustrated in FIG. 32, the window region 30 is formed in a square shape, and the width W1 of the protruding portion 20 in the end surface vicinity region 30A including the window region 30 is defined as the window region. It may be made larger than 30 width W3. In that case, the shape of the window region 30 is not limited to a square shape, and may be any shape.

  Further, in the above-described embodiment, the case where the p-side electrode 41 is formed on the contact layer 18 and the current blocking layer 21 has been described. However, as shown in FIG. You may make it form directly on the upper surface of the strip part 20, and the upper surface of the etching stop layer 16 of both sides. The impurity concentration is extremely low below and outside the side surface of the ridge 20, and the p-type third cladding layer 17 and the contact layer 18 are exposed to the atmosphere or water in the process of forming the ridge 20. As a result, an oxide layer (not shown) is formed on the surface, so that a Schottky junction is formed.

  In addition, the material and thickness of each layer, the film formation method, and the film formation conditions described in the above embodiment are not limited, and other materials and thicknesses may be used, or other film formation methods and film formation may be performed. It may be film conditions. For example, in the above-described embodiment, the mixed solution of citric acid and hydrogen peroxide is used as the etchant used when forming the protrusions 20, but other organic acids such as tartaric acid can also be used. It is.

  Furthermore, for example, in the above-described embodiment, the case where the etching stop layer 16 is left when the protrusions 20 are formed has been described. However, the etching stop layer 16 may be removed, or p Etching may be performed up to the middle of the mold second cladding layer 15.

  In addition, although the case where the window region 30 is formed by diffusing zinc (Zn) by the vapor phase diffusion method has been described in the above embodiment, a solid phase diffusion method using a ZnO film or the like may be used. .

  Furthermore, in the above embodiment, the case where the current blocking layer 21 is made of n-type GaAs has been described. However, if the current blocking layer 21 has the same conductivity type as that of the substrate 11, other layers such as AlGaAs mixed crystals can be used. These materials may be used, and any material may be selected in the design of the horizontal transverse mode. The structure for blocking current can be selected according to the design of the waveguide mechanism. For example, instead of providing the current blocking layer 21, an insulating film may be embedded. Alternatively, as shown in FIG. 33 described above, the p-side electrode 41 may be directly formed on the upper surface and both sides of the protrusion 20.

  In addition, in the above-described embodiment, the case where the p-type second cladding layer 15 and the p-type third cladding layer 17 have the same aluminum composition has been described, but the aluminum composition contained in both may be different. Good.

  Furthermore, for example, in the above-described embodiment, the case where the buffer layer 12 or the contact layer 18 is formed by a metal organic vapor phase epitaxy method such as the MOVPE method or the MOCVD method has been described. You may perform by MBE (Molecular Beam Epitaxy; Molecular beam epitaxy) method etc.

  In addition, in the above-described embodiment, the semiconductor laser element 10 having a configuration in which an n-type semiconductor layer, an active layer, and a p-type semiconductor layer are sequentially stacked on the n-type substrate 11 has been described. A reverse conductivity type structure in which a p-type semiconductor layer, an active layer, and an n-type semiconductor layer are stacked on a p-type substrate may be used.

  Furthermore, for example, in the above-described embodiment, the configuration of the semiconductor laser element 10 has been specifically described, but it is not necessary to include all layers, and other layers may be further included. For example, in the above embodiment, the n-type first cladding layer 13, the p-type second cladding layer 15, and the p-type third cladding layer 17 are each composed of one layer having one kind of aluminum composition. However, it may have a laminated structure of two or more layers having two or more kinds of aluminum compositions in terms of optical design.

  In addition, in the above embodiment, the case where the etching stop layer 16 is provided between the p-type second cladding layer 15 and the p-type third cladding layer 17 has been described. The etching stop layer 16 may be omitted by controlling the aluminum composition contained so that the p-type second cladding layer 15 also serves as the etching stop layer 16. Alternatively, the etching stop layer 16 and the p-type second cladding layer 15 may have the same aluminum composition.

  Furthermore, for example, in the above embodiment, the case where the contact layer 18 in the end face vicinity region 30A including the window region 30 is removed has been described. However, the contact layer 18 in the end face vicinity region 30A is not removed and is left as it is. May be. In this case, the width of the contact layer 18 in the end face vicinity region 30A may be the same as the width W1 of the protrusion portion 20 in the end face vicinity region 30A, or the width W2 of the protrusion portion 20 in the element internal region 30B. It may be the same.

  In addition, in the above-described embodiment, the case where the p-side electrode 41 and the n-side electrode 42 are formed in a rectangular pattern has been described. However, the present invention is not limited to this. For example, in the resonator direction or the resonator direction It may extend in a direction perpendicular to the substrate or may be formed on the entire substrate 11.

  Furthermore, in the above embodiment, the case where zinc (Zn) is diffused as an impurity in the window region 30 has been described, but the impurity diffused in the window region 30 may be silicon (Si).

  In addition, in the above-described embodiment, the case where the window region 30 is formed on both the main emission side end surface 10F and the rear end surface 10R has been described. However, the window region 30 is formed on both the main emission side end surface 10F and the rear end surface 10R. It does not need to be formed, and may be formed at least on the main emission side end face 10F.

  Furthermore, Modification 2 can be applied not only to the manufacturing method of the above-described embodiment, but also to the manufacturing method of Modification 1.

1 is a perspective view illustrating an overall configuration of a semiconductor laser array according to an embodiment of the present invention. FIG. 2 is an enlarged perspective view of the semiconductor laser element shown in FIG. FIG. 3 is a top view of the semiconductor laser element shown in FIG. 2. It is a figure showing the aluminum composition distribution of the active layer in the semiconductor laser element shown in FIG. It is a figure showing the flow of the manufacturing method of the semiconductor laser element shown in FIG. It is a perspective view showing the manufacturing method shown in FIG. 5 in order of a process. FIG. 7 is a perspective view illustrating a process following FIG. 6. FIG. 8 is a perspective view illustrating a process following FIG. 7. FIG. 9 is a perspective view illustrating a process following FIG. 8. FIG. 10 is a perspective view illustrating a process following FIG. 9. It is sectional drawing along the XI-XI line of FIG. It is sectional drawing along the XII-XII line | wire of FIG. FIG. 11 is a perspective view illustrating a process following FIG. 10. It is sectional drawing along the XIV-XIV line | wire of FIG. It is sectional drawing along the XV-XV line | wire of FIG. FIG. 14 is a perspective view illustrating a process following FIG. 13. FIG. 17 is a perspective view illustrating a process following the process in FIG. 16. FIG. 14 is a perspective view illustrating a process following FIG. 13. It is sectional drawing along the XIX-XIX line | wire of FIG. It is sectional drawing along the XX-XX line of FIG. FIG. 19 is a perspective view illustrating a process following the process in FIG. 18. FIG. 22 is a perspective view illustrating a process following the process in FIG. 21. FIG. 23 is a perspective view illustrating a process following the process in FIG. 22. It is a figure showing the flow of the manufacturing method of the semiconductor laser element which concerns on the modification 1 of this invention. FIG. 25 is a perspective view illustrating the manufacturing method illustrated in FIG. 24 in the order of steps. FIG. 26 is a perspective view illustrating a process following the process in FIG. 25. FIG. 27 is a perspective view illustrating a process following the process in FIG. 26. FIG. 28 is a cross-sectional diagram illustrating a process following the process in FIG. 27. FIG. 29 is a cross-sectional diagram illustrating a process following the process in FIG. 28. It is a figure showing the flow of the manufacturing method of the semiconductor laser element which concerns on the modification 2 of this invention. FIG. 31 is a perspective view illustrating a step of the manufacturing method illustrated in FIG. 30. It is a top view showing the structure of the semiconductor laser element which concerns on the modification of this invention. It is a perspective view showing the structure of the semiconductor laser element which concerns on the other modification of this invention. It is sectional drawing showing the example of 1 structure of the conventional semiconductor laser element. FIG. 35 is a cross-sectional view showing a method of manufacturing the conventional semiconductor laser element shown in FIG. 34 in the order of steps. FIG. 36 is a perspective view illustrating a process illustrated in FIG. FIG. 36 is a perspective view illustrating a process illustrated in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Semiconductor laser array, 10 ... Semiconductor laser element, 10F ... Main emission side end surface, 10R ... Back end surface, 11 ... Substrate, 12 ... Buffer layer, 13 ... First n-type cladding layer, 14 ... Active layer, 15 ... p Type second cladding layer, 16 ... etching stop layer, 17 ... p-type third cladding layer, 18 ... contact layer, 20 ... projection, 21 ... current blocking layer, 30 ... window region, 30A ... near end face region, 30B ... element internal region, 31 ... disordered region, 41 ... p-side electrode, 42 ... n-side electrode

Claims (16)

A semiconductor layer having a first clad layer, an active layer, a second clad layer, an etching stop layer, a third clad layer, and a contact layer in order on a substrate, the first clad layer, the active layer, the second clad layer The etching stop layer and the third cladding layer include at least aluminum (Al) and gallium (Ga) among group 3B elements and at least arsenic (As) among group 5B elements. The contact layer is made of GaAs, the third cladding layer and the contact layer are protrusions for limiting the stripe region of the active layer, and the protrusions are formed on the side surfaces of the semiconductor layer. Bei example a pair of resonator end surface opposed to the extending direction of the ridges,
A window region for suppressing absorption of light generated in the active layer is formed on at least one of the resonator end surfaces, and the width W1 of the protrusion in the region near the end surface including the window region is much larger than the width W2 in the region other than the region near the end surface, and is at the window region width W3 or more, the dimension LA in the resonator direction from the cavity end face of the edge surface vicinity region, the resonance of the window region Larger than the dimension LW in the cavity direction from the cavity end face
Broad stripe type semiconductor laser device. The contact layer is that provided by avoiding the region near the end surface including the window area
Broad-stripe semiconductor laser device 請 Motomeko 1 wherein. Current blocking layer that are formed on both sides of the ridge
Broad-stripe semiconductor laser device 請 Motomeko 1 wherein. Electrodes that are formed on the upper surface and both sides of the ridge
Broad-stripe semiconductor laser device 請 Motomeko 1 wherein. The etching stop layer and the third cladding layer are made of AlGaAs mixed crystal, and the aluminum composition contained in the third cladding layer is lower than the aluminum composition contained in the etching stop layer, and the difference is 0.025. broad-stripe semiconductor laser device of der Ru claim 1, wherein more. The window region including a silicon (Si) or zinc (Zn) as an impurity
Broad-stripe semiconductor laser device 請 Motomeko 1 wherein. A broad stripe semiconductor laser array in which a plurality of broad stripe semiconductor laser elements are arranged in parallel,
The broad stripe semiconductor laser element is:
A semiconductor layer having a first clad layer, an active layer, a second clad layer, an etching stop layer, a third clad layer, and a contact layer in order on a substrate, the first clad layer, the active layer, the second clad layer The etching stop layer and the third cladding layer include at least aluminum (Al) and gallium (Ga) among group 3B elements and at least arsenic (As) among group 5B elements. The contact layer is made of GaAs, the third cladding layer and the contact layer are protrusions for limiting the stripe region of the active layer, and the protrusions are formed on the side surfaces of the semiconductor layer. Bei example a pair of resonator end surface opposed to the extending direction of the ridges,
A window region for suppressing absorption of light generated in the active layer is formed on at least one of the resonator end surfaces, and the width W1 of the protrusion in the region near the end surface including the window region is much larger than the width W2 in the region other than the region near the end surface, and is at the window region width W3 or more, the dimension LA in the resonator direction from the cavity end face of the edge surface vicinity region, the resonance of the window region Larger than the dimension LW in the cavity direction from the cavity end face
Broad stripe semiconductor laser array.   The etching stop layer and the third cladding layer are made of AlGaAs mixed crystal, and the aluminum composition contained in the third cladding layer is lower than the aluminum composition contained in the etching stop layer, and the difference is 0.025. That's it
  The broad stripe type semiconductor laser array according to claim 7. A semiconductor layer having a first cladding layer, an active layer, a second cladding layer, an etching stop layer, a third cladding layer, and a contact layer in order is formed on a substrate, and the first cladding layer, the active layer, and the second cladding are formed. III-V group compound containing at least aluminum (Al) and gallium (Ga) of group 3B elements and at least arsenic (As) of group 5B elements, the layer, the etching stop layer, and the third cladding layer A step of configuring the contact layer with GaAs, and comprising a semiconductor ;
Forming a window region for suppressing absorption of light generated in the active layer by diffusing impurities into at least one of the planned formation positions of the pair of resonator end faces in the semiconductor layer;
The contact layer and a part of the third cladding layer are etched away until the etching stop layer is exposed to form a protrusion for limiting the stripe region of the active layer, and the window region the width W1 of the protruding portion in the region near the end surface including, much larger than the width W2 in the region other than the edge surface vicinity region, and a width W3 over the window region, formation of the cavity end face of the edge surface vicinity region Making the dimension LA in the resonator direction from the planned position larger than the dimension LW in the resonator direction from the planned position of forming the resonator end face of the window region ;
Method for producing a broad stripe semiconductor laser device comprising the steps of forming a pair of resonator end surface opposed to the extending direction of the ridges on the side surface of the semiconductor layer. In the step of forming the semiconductor layer, the etching stop layer and the third cladding layer are made of an AlGaAs mixed crystal, and the aluminum composition contained in the third cladding layer is more than the aluminum composition contained in the etching stop layer. And make the difference 0.025 or more,
  In the step of forming the protrusion, when the contact layer and a part of the third cladding layer are removed by etching, a mixed solution of an aqueous citric acid solution and a hydrogen peroxide solution is used as an etchant.
  A method for manufacturing a broad stripe type semiconductor laser device according to claim 9. After forming the ridges, remove the contact layer in the region near the end surface including the window area
請 Motomeko 9 manufacturing method of a broad-stripe semiconductor laser device according. Wherein after forming the semiconductor layer, removing the contact layer of at least one and the vicinity thereof to be formed position of the cavity end face, then form the window region
請 Motomeko 9 manufacturing method of a broad-stripe semiconductor laser device according. After forming the ridge, that to form a current blocking layer on both sides of the ridge
請 Motomeko 9 manufacturing method of a broad-stripe semiconductor laser device according. After forming the ridges, form electrodes on the upper surface and both sides of the ridge
請 Motomeko 9 manufacturing method of a broad-stripe semiconductor laser device according. In the step of forming the semiconductor layer, the etching stop layer and the third cladding layer are made of an AlGaAs mixed crystal, and the aluminum composition contained in the third cladding layer is more than the aluminum composition contained in the etching stop layer. And make the difference 0.025 or more,
In the step of forming the protrusion, when removing a part of the contact layer and the third cladding layer by etching, a plurality of different etchants are used , and at least the last step is performed as an etchant. Performed using a mixture of citric acid aqueous solution and hydrogen peroxide solution
請 Motomeko 9 manufacturing method of a broad-stripe semiconductor laser device according. The broad stripe type semiconductor laser according to claim 15 , wherein, when a part of the semiconductor layer is removed by etching, the remaining part of the semiconductor layer is washed with an aqueous citric acid solution at least between the last step and the immediately preceding step. Device manufacturing method.

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